Are There Fish In Our Future... Or is 2048 the Y2K for Seafood?

by Sheril R. Kirshenbaum     Department: Health & Life Sciences

We humans long believed oceans must be so enormous, the abundance of resources in the marine realm had to be limitless.  We're funny about holding onto notions like that...

More recently, we woke up and figured out this idea of an imagined boundless supply is pretty ridiculous. While it's not easy to observe the web of complex interactions below the surface, we've learned enough about fish stocks to understand we're actually impacting them tremendously through our fishing practices.  Just consider the state of oceans in 2008...

The Bad News

You've probably heard that infamous prediction:  Scientists tell us the world's fish and seafood populations will collapse by 2048.  Maybe they will.  According Boris Worm - lead author of the study:

When ocean species collapse, it makes the ocean itself weaker and less able to recover from shocks like global climate change.

Okay, I'm seeing some red flags... After all, we do know that the majority of the world's fisheries are currently overfished and many commercial species are at risk of extinction - mostly because we've been placing so much pressure on them through harvesting practices.  Entire fisheries for sturgeons, salmon, tuna and on... are collapsing.  Not good.

So what's going on?  Why in the 21st century can't managers figure out how to fix the problem?  Now I know what you're thinking--given so many aquatic species reproduce in large numbers, how hard can this be?  They ought to recover quickly.  If only...

The trouble is, governance itself is pretty complicated - and that's the biggest piece of the puzzle.  Management's tricky, especially when you keep in mind stocks are more than a story of numbers.  So if rules are established that only consider a population's size, selective extraction methods that can alter structure and stability of the species are ignored.  And what's that mean?  

Well, imagine you're a fisherman using a net that selects the largest animals.  The big (oldest) individuals - females specifically - are also those who would otherwise expect to contribute the most offspring to the next generation.  So while initially numbers of a fished stock may seem stable, it's possible that disproportionate reproductive success among survivors changes total fitness overall.   There you have it... The very characteristic (size) that has historically resulted in higher success now puts animals most at risk.  Remaining fish are less prolific and the next cohort may be significantly smaller.  In other words, a mere numbers model based on maximum sustainable yield may not be as practical when you consider factors that shift the population structure.

But let's say we've accounted for gear--we're in good shape, right?  Not necessarily.  Certain methods of harvest are destructive like dynamite fishing, dredging, bottom trawling, and so on.  Multiply those factors with marine mammal collisions, trophic (food chain) cascades, lots of pollution, bycatch... It's enough to make this marine scientist dizzy!

So what's a good manager to do?  Well, it's not all doom and gloom.

The Good News

Fishing can be done responsibly and sustainably.  It's true.  And sound governance plays the vital role.  Decisions must balance harvest rate in response to socio-political and economic pressures.  Okay, easier said than done. Sure, there are more than a few factors that complicate things--altered population structure, institutional norms, history of the industry, control, information problems, transaction costs, externalities, uncertainty, and beyond....

At first glance it's enough to make anyone throw up their hands proclaiming the problem is just too big.  But there's a realistic balance between achieving the highest profit while maintaining a sustainable population.  How? 

Effective user incentives based on the biology and socio-economics of associated communities on a case by case basis.  By working across local and regional scales, we'll achieve healthy stocks. 

Enter Ecosystem Based Management (EBM).  EBM focuses on cumulative effects of complex relationships and also addresses the human component. Pretty good idea, no?  Socioeconomic pressures are emphasized so that new initiatives are practical in the real world. It's a holistic scheme rather than dealing with individual species piecemeal.

Will it be successful?  Depends how you define success...  Really, EBM is more of a theory and approach to work out from, and not a goal in itself.  But at the least it's a good place to begin.  It gives me assurance that we're beginning to understand the big picture in a more realistic way.  And that in itself is small step closer to sustainable seafood in 2049.

My perspective of Ecosystem Based Management here.

Tags: collapse, Fisheries, Fishing

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